This application is for an iCyt Reflection System Fluorescence Activated Cell Sorter to be housed in the Flow Cytometry and Microscopy Core Facility at National Jewish Health. National Jewish investigators have extensive experience in cell sorting, and 22 investigators (8 major users and 14 minor users;all but one of whom has current NIH support) require access to cell sorting for their projects. Until recently National Jewish Health had 2 functional cell sorters, but in the past year both of these instruments have broken down and become obsolete. These instruments are almost 15 years old and, even if repairing them was possible, they would still not serve the needs of National Jewish Health investigators. The current technology for cell sorting is far superior to the capabilities of the old instruments and includes high speed sorting;biosafety containment;detection of multiple fluorochromes and multiple lasers. The iCyt Reflection system is the ideal instrument for the NJH core facility because it has all of the capabilities needed by the investigators and it has a modular design that will enable the institution to purchase additional modules that can operate in parallel and utilize the same lasers. The core facility has 3 operators (a director and 2 technicians) with 15, 19 and 8 years of experience with similar instrumentation. We have developed a funding model that will ensure that the instrument will operate to its capacity and will receive the highest standards of maintenance.